[Helicobacter pylori infection and histological types of gastric cancer]

The relationship between Helicobacter pylori (H. pylori) infection and gastric cancer was evaluated clinicopathologically by histological types of gastric cancer (intestinal or diffuse type). Histological findings of resected stomach tissues and serum anti-H. pylori IgG antibody titers obtained in patients with early gastric cancer revealed H. pylori infection and associated inflammatory changes in all cases, irrespective of histological types of cancer, and suggested that diffuse type cancer occurs in the mucosa with marked inflammation at a relatively early stage of H. pylori infection, while intestinal type cancer occurs at a relatively late stage of infection in parallel with the progression of mucosal atrophy and intestinal metaplasia. Results of immunohistochemical staining showed high incidence of secretory components in and around cancer foci, suggesting that immunological mechanisms for H. pylori infection play a role in the development of gastric cancer regardless of its histological type.